Abstract: An automated storage system uses a pass-through picker assembly interposed between a storage device and a plurality of storage cells, wherein the pass-through picker assembly is mounted on an accessor and incorporates independently operating fore and aft grippers driven by a single motor. The fore and aft grippers are tandemly mounted such that the fore gripper can be aligned to one of a plurality of storage cartridges located with the storage cells, and the aft gripper can be aligned with a storage slot of the storage device. The pass-through picker design allows the fore gripper to grasp a storage cartridge, feed the cartridge through to the aft gripper, release, and then allow the aft gripper to grip and pass the storage cartridge to the storage slot. In this way, a special priority cell of the storage cells, directly across from the storage slot, can very quickly pass a priority storage cartridge directly to the storage device without moving the pass-through picker assembly.

Abstract: A write-once read-many (WORM) optical disk recorder automatically calibrates its laser to emit a laser beam of a desired power level. While writing data to the WORM disk, a laser test signal is written to a laser checking area termed Automatic Laser Power Correction (ALPC) field. If the emitted laser test signal has a power level outside an acceptable power level window, then inappropriate laser power is indicated. Then, in an error recovery procedure (ERP) the laser power is calibrated in the data sector to be written to using short spaced-apart laser test signals. After successful calibration, data are written to the sector. The test signals appear as burst errors that can be corrected by a suitable error correction code. If such calibration is not successful then a write calibrate sector, WCS, is created and used for an extensive automatic calibration. In the WCS both laser power level is calibrated. The calibration result information is written to WCS for later use.

Abstract: A light intensity, direct overwrite, magneto-optical system generates signals such that, during the formation of a recording mark on an optical disk, a laser is driven a) at a pedestal power level, then b) at a quench power level for a first quench period t.sub.1, the quench power level being less than the pedestal power level, then c) at a write power level for a write period t.sub.2 whereby the reference bit becomes oriented in the writing direction, the write power level being greater than the pedestal power level, then d) at the quench power level for a second quench period t.sub.3, and then e) at the pedestal power level until the formation of another recording mark begins. The system is provided with a controller to determine optimal lengths of the quench periods t.sub.1 and t.sub.3, thereby reducing thermal interference between closely spaced recording marks. From sample recording marks, recorded with different quench periods t.sub.1 and t.sub.

Abstract: A laser read beam power level is increased with increasing radii and decreased with decreasing radii of scanning a spiral track in an optical disk. The change of read beam power level is adjusted in accordance with an established erasure profile. The erasure profile indicates beam power level at various radii at which recorded data are erased, such as in a magneto-optical disk. Read beam power level is adjusted from a pre-established minimum read beam power level (used at an inner disk radius) following the erasure profile. This action maximizes read power level without exceeding the erasure profile indicated power levels. Radial ranges are established for reading from the optical disk. Within each range, the laser beam read power level is kept constant, preferably at the desired power level at an radially inner-most portion of the respective range. Optical disks have the minimum laser read beam power level and an erasure profile recorded therein.

Abstract: The present invention provides machine and human readable information for a data cartridge or other item to be stored. In one embodiment, a label, on which human readable information is printed or similarly marked, is applied to cover an indicator area of the cartridge. The indicator area of the cartridge has recesses formed therein; corresponding positions on the indicator area of the label overlay the recesses and be either open or closed. An open position allows a mechanical, spring-loaded finger on a data drive to engage the exposed recess and activate or deactivate a connected switch. Information, matching the printed human readable information, can thus be encoded in the label and machine read by the data drive.

Abstract: In a magnetic tape drive, a magnetic head simultaneously senses plural track lateral position indicators to generate a like plurality of independently generated sensed position error signals. The sensed position error signals are combined to provide an output position error signal that drives a positioning system to position the magnetic laterally of the length of the magnetic tape. The output position error signal represents an average of the position errors indicated by the sensed position error signals. The quality of the sensed position error signal is monitored, enabling eliminating poor quality signals from the output position error signal for maintaining a quality servo control. If less than a predetermined number of sensed position error signals have acceptable quality, then recording data is prohibited. Independently of sensing servo indicia on a record member to generate the sensed position error signals, a lateral position of the multi-track head is sensed.

Abstract: A media library system has a plurality of independently-operated library arrays disposed in a side-by-side relationship along a first direction. Each of the library arrays has a media drive and a plurality of media storage receptacles arranged in a second direction that is transverse to the first direction. A separate media transport apparatus in each of the library arrays has a moveable media holder for moving media along the second direction between the storage receptacles in the library arrays and the media drives, respectively, in the independently-operated library arrays. A media exchanging and input common apparatus has a media carrier disposed for movement adjacent a common end of all of the independently-operated library arrays along the first direction. The media carrier has a media-transfer stop location at each of the library arrays at the common end of each of the library arrays.

Abstract: In a write-once read-many (WORM) optical disk device recorded unipolar pulse signals having a high lineal recorded densities are read back using an inverted analog signal processing channel that processes the read back signal after polarity inversion of the read back signal. Some fields in each sector of an optical disk are recorded at a specific maximal mark density pattern. Read back of such fields is signal processed using non-inverted read back analog signal processing, i.e. the read back unipolar pulse signal is processed without polarity inversion. In the non-inverted read back, automatic gain control of the read signal is turned off such that amplification of the read back signal is at a constant gain. Also during non-inverted read back, low read back signal amplitude results in degating the read back output.

Abstract: An optical device has an optical array detector with an array of optical receptors (each receptor is an individual photo detector) that has a greater cross-sectional extent than an impinging light beam. The receptors have respective light receiving areas smaller than the a cross-sectional area of the impinging light beam. A ring lens passes a received light beam to the receptor array. A ring lens refracts a defocused and off-track impinging light beam whereby the optical refractive properties of the ring lens change the cross-sectional form of the received light beam in accordance with status of the light beam. Refraction of the received light beam in the ring lens distorts the beam cross-sectional shape for indicating focus and location errors. Provisions are made for automatic calibration of the impinging beam to a current position of the array detector physical position by the optical device. Optical detection and re-calibration is effected by a digital signal processor.

Abstract: The present invention provides a storage system having a programmable controller which recognizes the amount of storage capacity paid for by a customer, even if more physical capacity is actually installed. When the customer purchases additional capacity, the controller is directed to recognize the additional capacity and permit access thereto.

Abstract: A gear constructed of a monolithic material having a first reflectivity and having one or more projections is interlocked into a cam constructed of a monolithic material having a second reflectivity substantially different from the first reflectivity. The one or more projections are mated with corresponding one or more openings in the gear whereby such mating provides a torsional lock. A reflective sensor having a focal length corresponding to either a surface of the projections or a surface of the cam detects positions of the gear by transitions from reflective to non-reflective surfaces and vice versa. The detected transitions are used to provide feedback control to a motor driving the gear.

Abstract: Primary and secondary data processing systems are coupled via a communication system. Data storage in both systems is provided by a log structured array (LSA) system that stores data in compressed form. Each time data are updated within LSA, the updated data are stored in a data storage location different from the original data. Selected data recorded in a primary data storage of the primary system is remote dual copied to the secondary system for congruent storage in a secondary data storage, such as for disaster recovery purposes. The primary systems creates a remote copying session. Within such remote copying session, a series of "pending write update" sessions are ESTABLISHED. All data updated within each pending write update session is a consistency group of data. Within each pending write update session update data are retentively stored in both the primary and secondary systems (such as in a non-volatile cache).

Abstract: A coarse position sensor is provided for an optical recording device to generate a substantially linear coarse position signal, indicative of the position of a coarse carriage along the range of its travel, and which also is substantially immune to environmental and device variations. The sensor includes a light source mounted to a drive frame at one end of the range of travel, a position sensitive device fixed to the frame at the opposite end of the range of travel and facing the light source, and a deflecting optical element mounted to the coarse carriage in the path of the light. As the coarse carriage travels along its stroke between the inner and outer diameters of the optical disk, the amount of deflection of the light beam on the position sensitive device from a reference location will change.

Abstract: The present invention provides efficient management of calibration and spare sectors on a banded optical write-once, read-many (WORM) disk. A portion of each band on the disk includes a user data area and a reserved area. Sectors in the reserved area are usable either as spare sectors, replacing defective sectors in the user area, or as calibration sectors, for use when the laser write-power level is calibrated. Sectors preferably are used for sparing from one end of the reserved area while sectors are used for calibration from the opposite end. A common overflow reserved area can also be provided for use if all of the sectors in one or more primary reserved areas associated with any of the bands have been exhausted.

Abstract: A peripheral data storage subsystem has means for responding to a MOUNT command received from a host processor to create and mount a host-processor-addressable logical data-storage volume. Such logical data-storage volume has a serial number VOLSER indicated in the MOUNT command. The logical data volume is assigned a predetermined area of a physical data volume, such area being termed a partition. The illustrated embodiment shows a tape subsystem in which the partitions are accessed by a control using a reel tachometer that identifies segments of the tape. Each partition has a number of the tape segments. Controls and methods are described for initializing the subsystem for effecting the automatic volume creation, appending data into a logical volume, how logical volumes are made to be portable, moving logical volumes amongst diverse physical media, tape formats usable for such logical volumes, data base control of the logical volumes and volume creation processing.

Abstract: The present invention provides a method and apparatus for reducing the overhead required in conventional fault tolerant processing by redundant processors. Commands are received and queued by both the active and standby units but are processed only by the active unit. Short messages, each including a command identifier, are transmitted from the active unit to the standby unit. In addition, periodic handshaking signals are exchanged between the two units. In the event the active unit fails, the standby unit is automatically brought on-line to process the unprocessed commands and transmit responses to the command source. When the failed unit is restored, it can become the standby unit.

Abstract: A pass-thru cassette magazine performs several functions beyond vertically holding a plurality of data cassettes in a position randomly accessible to a data storage subsystem picker assembly, including locking the data cassettes within corresponding storage cells in either an import or export position when the magazine is not interfaced to the storage subsystem (that is during handling by an operator). The "locked" position indicates that a data cassette cannot be removed from the magazine without a force of approximately one kilogram or greater. When a magazine is interfaced to the storage subsystem, the magazine is interlocked thereto such that the magazine cannot be removed without releasing the interlock. While the magazine is interlocked, the lock on the data cassettes is disabled so that the data cassettes can be freely picked by the picker assembly or removed or inserted by an operator.

Abstract: A system for recording on a rewritable (erasable) optical disk is provided which reduces the data integrity exposure and negative performance impact of separate erase and write passes when writing data to such a disk in a disk drive. In a preferred embodiment, the system includes a non-volatile storage buffer established and maintained by a driver at a level below the file system. Space in the buffer is kept pre-erased for temporarily storing blocks of data transmitted by a host device and destined for sectors in a logical partition on a rewritable optical disk. Mapping and control information are also maintained in the buffer. In a background operation, transparent to the host, the blocks of data are copied from the buffer to their destination sectors in the logical partition. The buffer can be located on the optical disk itself or can be on a separate device, such as non-volatile random access memory or magnetic media.

Abstract: A data storage system provides the data security afforded by write-once, read-many storage media and the lower cost afforded by rewritable storage media. To effectively write protect data, the system generates a protective code based upon the data to be stored, stores the protective code and a data identification on WORM media and stores the data and the location of the protective code on rewritable media. When the data is later read, it is verified by reading the data, generating a new protective code from the data and comparing the new code with the original code. Any difference between the two protective codes indicates that the data has been altered.

Abstract: The present invention provides a method and an apparatus to accurately and consistently distinguish blank sectors from written sectors on optical media despite drive and media variations. A readback envelope threshold is established each time optical media is mounted into an optical drive. In one embodiment, the gain of readback amplifiers are set to a first level, the optical head seeks to and reads a sector or set of sectors on the optical disk known to have information recorded thereon and a first readback envelope generated. The gain of the readback preamplifier is then set to a second level, the optical head seeks to and reads another sector or set of sectors known to have information recorded thereon and a second readback envelope generated. The readback threshold is calculated from the amplitudes of the first and second envelopes.